Java 1.4.2. - full heap dump?

Question

Hello,
Is there any possibility to generate full heap dump (core dump) in java 1.4.2. on demand?
Best regards,
Peter

Answer 1

If you are in Unix platform, you can use this script to have thread dump.
I am not sure whether you can generate coredump with out an application crash .
kill -3 <java pid> will provide full stacktrace of the java process thread dump.
Note: kill -3 will not terminate the java process, it will only generate full stacktrace in your log file and safe to use while the java process is running.
you can get the java process id, using this unix cmd "ps -ef | grep java" .
#!/bin/ksh
[ $# -le 0 ] && echo "USAGE: $0 <pid>" && exit
for i in 1 2
do
DT=`date +%Y%m%d_%H%M`
prstat -Lmp $1 1 1 >> prstat_Lmp_$i_$DT.dmp
pstack $1 >> pstack_$i_$DT.dmp
kill -3 $1
echo "prstat, pstack, and thread dump done. #" $i
sleep 1
echo "Done sleeping."
done
Pls go through some of this links, this will provide you on how to debug the issue with the logs generated by the scripts:
http://support.bea.com/application_content/product_portlets/support_patterns/wls/UnexpectedHighCPUUsageWithWLSPattern.html
http://www.unixville.com/~moazam/stories/2004/05/18/debuggingHangsInTheJvm.html